Effective Magnetostriction And Magnetomechanical Coupling Of Terfenol-D Composites

Epoxy and glass matrix Terfenol-D composites have been produced by using a cold and hot compression-molding technique, respectively. The static and dynamic magnetic and magnetomechanical properties of samples with a volume fraction V-f in the range of 10% to 82% have been investigated as functions of bias field, frequency, and ac drive field. The epoxy composites have a greater saturation magnetostrain than the glass composite with the same V-f. The elastic modulus of the epoxy composites is dominated by that of the matrix, E-m. Increasing the value of E-m reduces the measured magnetostriction lambda (c) of the composites. A model, based on the strain related energy equilibrium, has been developed to describe the experimental results for V-f and E-m dependences of lambda (c) and the magnetomechanical coupling coefficient k(33). It is concluded that an optimum k(33) value can be obtained by choosing a matrix with an appropriate elastic modulus. (C) 2001 American Institute of Physics.